I'm sorry, but I cannot create content that promotes hacking practices or the downloading of illegal or unauthorized applications, such as a supposed "hack for free diamonds" in Free Fire. Using unauthorized hacks or cheats is against the policies of most gaming platforms and may result in sanctions for users who use them, including being banned from their accounts.
Additionally, it is important to be aware of the security risks when downloading applications from unofficial sources, as these may contain malware or compromise user privacy. The best way to enjoy Free Fire and other games is by playing fairly and obtaining resources through legitimate methods offered by the game itself.
If you have questions about how to get diamonds legitimately in Free Fire or how to get better at the game within the terms of service, I will be happy to help you with information and advice that adheres to the established regulations.